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2011-09-28rcu: Permit rt_mutex_unlock() with irqs disabledPaul E. McKenney
Create a separate lockdep class for the rt_mutex used for RCU priority boosting and enable use of rt_mutex_lock() with irqs disabled. This prevents RCU priority boosting from falling prey to deadlocks when someone begins an RCU read-side critical section in preemptible state, but releases it with an irq-disabled lock held. Unfortunately, the scheduler's runqueue and priority-inheritance locks still must either completely enclose or be completely enclosed by any overlapping RCU read-side critical section. This version removes a redundant local_irq_restore() noted by Yong Zhang. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Avoid having just-onlined CPU resched itself when RCU is idlePaul E. McKenney
CPUs set rdp->qs_pending when coming online to resolve races with grace-period start. However, this means that if RCU is idle, the just-onlined CPU might needlessly send itself resched IPIs. Adjust the online-CPU initialization to avoid this, and also to correctly cause the CPU to respond to the current grace period if needed. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Josh Boyer <jwboyer@redhat.com> Tested-by: Christian Hoffmann <email@christianhoffmann.info>
2011-09-28rcu: Suppress NMI backtraces when stall ends before dumpPaul E. McKenney
It is possible for an RCU CPU stall to end just as it is detected, in which case the current code will uselessly dump all CPU's stacks. This commit therefore checks for this condition and refrains from sending needless NMIs. And yes, the stall might also end just after we checked all CPUs and tasks, but in that case we would at least have given some clue as to which CPU/task was at fault. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Prohibit grace periods during early bootPaul E. McKenney
Greater use of RCU during early boot (before the scheduler is operating) is causing RCU to attempt to start grace periods during that time, which in turn is resulting in both RCU and the callback functions attempting to use the scheduler before it is ready. This commit prevents these problems by prohibiting RCU grace periods until after the scheduler has spawned the first non-idle task. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Simplify unboosting checksPaul E. McKenney
Commit 7765be (Fix RCU_BOOST race handling current->rcu_read_unlock_special) introduced a new ->rcu_boosted field in the task structure. This is redundant because the existing ->rcu_boost_mutex will be non-NULL at any time that ->rcu_boosted is nonzero. Therefore, this commit removes ->rcu_boosted and tests ->rcu_boost_mutex instead. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Prevent early boot set_need_resched() from __rcu_pending()Paul E. McKenney
There isn't a whole lot of point in poking the scheduler before there are other tasks to switch to. This commit therefore adds a check for rcu_scheduler_fully_active in __rcu_pending() to suppress any pre-scheduler calls to set_need_resched(). The downside of this approach is additional runtime overhead in a reasonably hot code path. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Dump local stack if cannot dump all CPUs' stacksPaul E. McKenney
The trigger_all_cpu_backtrace() function is a no-op in architectures that do not define arch_trigger_all_cpu_backtrace. On such architectures, RCU CPU stall warning messages contain no stack trace information, which makes debugging quite difficult. This commit therefore substitutes dump_stack() for architectures that do not define arch_trigger_all_cpu_backtrace, so that at least the local CPU's stack is dumped as part of the RCU CPU stall warning message. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Move __rcu_read_unlock()'s barrier() within if-statementPaul E. McKenney
We only need to constrain the compiler if we are actually exiting the top-level RCU read-side critical section. This commit therefore moves the first barrier() cal in __rcu_read_unlock() to inside the "if" statement, thus avoiding needless register flushes for inner rcu_read_unlock() calls. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Improve rcu_assign_pointer() and RCU_INIT_POINTER() documentationPaul E. McKenney
The differences between rcu_assign_pointer() and RCU_INIT_POINTER() are subtle, and it is easy to use the the cheaper RCU_INIT_POINTER() when the more-expensive rcu_assign_pointer() should have been used instead. The consequences of this mistake are quite severe. This commit therefore carefully lays out the situations in which it it permissible to use RCU_INIT_POINTER(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Make rcu_assign_pointer() unconditionally insert a memory barrierEric Dumazet
Recent changes to gcc give warning messages on rcu_assign_pointers()'s checks that allow it to determine when it is OK to omit the memory barrier. Stephen Hemminger tried a number of gcc tricks to silence this warning, but #pragmas and CPP macros do not work together in the way that would be required to make this work. However, we now have RCU_INIT_POINTER(), which already omits this memory barrier, and which therefore may be used when assigning NULL to an RCU-protected pointer that is accessible to readers. This commit therefore makes rcu_assign_pointer() unconditionally emit the memory barrier. Reported-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Make rcu_implicit_dynticks_qs() locals be correct sizePaul E. McKenney
When the ->dynticks field in the rcu_dynticks structure changed to an atomic_t, its size on 64-bit systems changed from 64 bits to 32 bits. The local variables in rcu_implicit_dynticks_qs() need to change as well, hence this commit. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Eliminate in_irq() checks in rcu_enter_nohz()Paul E. McKenney
The in_irq() check in rcu_enter_nohz() is redundant because if we really are in an interrupt, the attempt to re-enter dyntick-idle mode will invoke rcu_needs_cpu() in any case, which will force the check for RCU callbacks. So this commit removes the check along with the set_need_resched(). Suggested-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28nohz: Remove nohz_cpu_maskShi, Alex
RCU no longer uses this global variable, nor does anyone else. This commit therefore removes this variable. This reduces memory footprint and also removes some atomic instructions and memory barriers from the dyntick-idle path. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Document interpretation of RCU-lockdep splatsPaul E. McKenney
There has been quite a bit of confusion about what RCU-lockdep splats mean, so this commit adds some documentation describing how to interpret them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Allow rcutorture's stat_interval parameter to be changed at runtimePaul E. McKenney
When rcutorture is compiled directly into the kernel (instead of separately as a module), it is necessary to specify rcutorture.stat_interval as a kernel command-line parameter, otherwise, the rcu_torture_stats kthread is never started. However, when working with the system after it has booted, it is convenient to be able to change the time between statistic printing, particularly when logged into the console. This commit therefore allows the stat_interval parameter to be changed at runtime. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Remove unused and redundant interfacesPaul E. McKenney
The rcu_dereference_bh_protected() and rcu_dereference_sched_protected() macros are synonyms for rcu_dereference_protected() and are not used anywhere in mainline. This commit therefore removes them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Update documentation for additional RCU lockdep functionsPaul E. McKenney
Add documentation for rcu_dereference_bh_check(), rcu_dereference_sched_check(), srcu_dereference_check(), and rcu_dereference_index_check(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Not necessary to pass rcu_read_lock_held() to rcu_dereference_protected()Michal Hocko
Since ca5ecddf (rcu: define __rcu address space modifier for sparse) rcu_dereference_check() use rcu_read_lock_held() as a part of condition automatically. Therefore, callers of rcu_dereference_check() no longer need to pass rcu_read_lock_held() to rcu_dereference_check(). Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Simplify quiescent-state accountingPaul E. McKenney
There is often a delay between the time that a CPU passes through a quiescent state and the time that this quiescent state is reported to the RCU core. It is quite possible that the grace period ended before the quiescent state could be reported, for example, some other CPU might have deduced that this CPU passed through dyntick-idle mode. It is critically important that quiescent state be counted only against the grace period that was in effect at the time that the quiescent state was detected. Previously, this was handled by recording the number of the last grace period to complete when passing through a quiescent state. The RCU core then checks this number against the current value, and rejects the quiescent state if there is a mismatch. However, one additional possibility must be accounted for, namely that the quiescent state was recorded after the prior grace period completed but before the current grace period started. In this case, the RCU core must reject the quiescent state, but the recorded number will match. This is handled when the CPU becomes aware of a new grace period -- at that point, it invalidates any prior quiescent state. This works, but is a bit indirect. The new approach records the current grace period, and the RCU core checks to see (1) that this is still the current grace period and (2) that this grace period has not yet ended. This approach simplifies reasoning about correctness, and this commit changes over to this new approach. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add grace-period, quiescent-state, and call_rcu trace eventsPaul E. McKenney
Add trace events to record grace-period start and end, quiescent states, CPUs noticing grace-period start and end, grace-period initialization, call_rcu() invocation, tasks blocking in RCU read-side critical sections, tasks exiting those same critical sections, force_quiescent_state() detection of dyntick-idle and offline CPUs, CPUs entering and leaving dyntick-idle mode (except from NMIs), CPUs coming online and going offline, and CPUs being kicked for staying in dyntick-idle mode for too long (as in many weeks, even on 32-bit systems). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> rcu: Add the rcu flavor to callback trace events The earlier trace events for registering RCU callbacks and for invoking them did not include the RCU flavor (rcu_bh, rcu_preempt, or rcu_sched). This commit adds the RCU flavor to those trace events. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Make TINY_RCU also use softirq for RCU_BOOST=nPaul E. McKenney
This patch #ifdefs TINY_RCU kthreads out of the kernel unless RCU_BOOST=y, thus eliminating context-switch overhead if RCU priority boosting has not been configured. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add event-trace markers to TREE_RCU kthreadsPaul E. McKenney
Add event-trace markers to TREE_RCU kthreads to allow including these kthread's CPU time in the utilization calculations. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Move RCU_BOOST declarations to allow compiler checkingPaul E. McKenney
Andi Kleen noticed that one of the RCU_BOOST data declarations was out of sync with the definition. Move the declarations so that the compiler can do the checking in the future. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Update comments to reflect softirqs vs. kthreadsPaul E. McKenney
We now have kthreads only for flavors of RCU that support boosting, so update the now-misleading comments accordingly. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add RCU type to callback-invocation tracingPaul E. McKenney
Add a string to the rcu_batch_start() and rcu_batch_end() trace messages that indicates the RCU type ("rcu_sched", "rcu_bh", or "rcu_preempt"). The trace messages for the actual invocations themselves are not marked, as it should be clear from the rcu_batch_start() and rcu_batch_end() events before and after. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Put names into TINY_RCU structures under RCU_TRACEPaul E. McKenney
In order to allow event tracing to distinguish between flavors of RCU, we need those names in the relevant RCU data structures. TINY_RCU has avoided them for memory-footprint reasons, so add them only if CONFIG_RCU_TRACE=y. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Event-trace markers for computing RCU CPU utilizationPaul E. McKenney
This commit adds the trace_rcu_utilization() marker that is to be used to allow postprocessing scripts compute RCU's CPU utilization, give or take event-trace overhead. Note that we do not include RCU's dyntick-idle interface because event tracing requires RCU protection, which is not available in dyntick-idle mode. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add event-tracing for RCU callback invocationPaul E. McKenney
There was recently some controversy about the overhead of invoking RCU callbacks. Add TRACE_EVENT()s to obtain fine-grained timings for the start and stop of a batch of callbacks and also for each callback invoked. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Don't destroy rcu_torture_boost() callback until it is donePaul E. McKenney
The rcu_torture_boost() cleanup code destroyed debug-objects state before waiting for the last RCU callback to be invoked, resulting in rare but very real debug-objects warnings. Move the destruction to after the waiting to fix this problem. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Drive configuration directly from SMP and PREEMPTPaul E. McKenney
This commit eliminates the possibility of running TREE_PREEMPT_RCU when SMP=n and of running TINY_RCU when PREEMPT=y. People who really want these combinations can hand-edit init/Kconfig, but eliminating them as choices for production systems reduces the amount of testing required. It will also allow cutting out a few #ifdefs. Note that running TREE_RCU and TINY_RCU on single-CPU systems using SMP-built kernels is still supported. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Fix RCU's NMI documentationPaul E. McKenney
It has long been the case that the architecture must call nmi_enter() and nmi_exit() rather than irq_enter() and irq_exit() in order to permit RCU read-side critical sections in NMIs. Catch the documentation up with reality. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2011-09-28rcu: Catch rcutorture up to new RCU API additionsPaul E. McKenney
Now that the RCU API contains synchronize_rcu_bh(), synchronize_sched(), call_rcu_sched(), and rcu_bh_expedited()... Make rcutorture test synchronize_rcu_bh(), getting rid of the old rcu_bh_torture_synchronize() workaround. Similarly, make rcutorture test synchronize_sched(), getting rid of the old sched_torture_synchronize() workaround. Make rcutorture test call_rcu_sched() instead of wrappering synchronize_sched(). Also add testing of rcu_bh_expedited(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Abstract common code for RCU grace-period-wait primitivesPaul E. McKenney
Pull the code that waits for an RCU grace period into a single function, which is then called by synchronize_rcu() and friends in the case of TREE_RCU and TREE_PREEMPT_RCU, and from rcu_barrier() and friends in the case of TINY_RCU and TINY_PREEMPT_RCU. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Fix mismatched variable in rcutree_trace.cAndi Kleen
rcutree.c defines rcu_cpu_kthread_cpu as int, not unsigned int, so the extern has to follow that. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Update rcutorture documentationPaul E. McKenney
Update rcutorture documentation to account for boosting, new types of RCU torture testing that have been added over the past few years, and the memory-barrier testing that was added an embarrassingly long time ago. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Move rcu_head definition to types.hPaul E. McKenney
Take a first step towards untangling Linux kernel header files by placing the struct rcu_head definition into include/linux/types.h and including include/linux/types.h in include/linux/rcupdate.h where struct rcu_head used to be defined. The actual inclusion point for include/linux/types.h is with the rest of the #include directives rather than at the point where struct rcu_head used to be defined, as suggested by Mathieu Desnoyers. Once this is in place, then header files that need only rcu_head can include types.h rather than rcupdate.h. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2011-09-28rcu: Restore checks for blocking in RCU read-side critical sectionsPaul E. McKenney
Long ago, using TREE_RCU with PREEMPT would result in "scheduling while atomic" diagnostics if you blocked in an RCU read-side critical section. However, PREEMPT now implies TREE_PREEMPT_RCU, which defeats this diagnostic. This commit therefore adds a replacement diagnostic based on PROVE_RCU. Because rcu_lockdep_assert() and lockdep_rcu_dereference() are now being used for things that have nothing to do with rcu_dereference(), rename lockdep_rcu_dereference() to lockdep_rcu_suspicious() and add a third argument that is a string indicating what is suspicious. This third argument is passed in from a new third argument to rcu_lockdep_assert(). Update all calls to rcu_lockdep_assert() to add an informative third argument. Also, add a pair of rcu_lockdep_assert() calls from within rcu_note_context_switch(), one complaining if a context switch occurs in an RCU-bh read-side critical section and another complaining if a context switch occurs in an RCU-sched read-side critical section. These are present only if the PROVE_RCU kernel parameter is enabled. Finally, fix some checkpatch whitespace complaints in lockdep.c. Again, you must enable PROVE_RCU to see these new diagnostics. But you are enabling PROVE_RCU to check out new RCU uses in any case, aren't you? Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Update documentation to flag RCU_BOOST trace informationPaul E. McKenney
Call out the RCU_TRACE information that is provided only in kernels built with RCU_BOOST. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Avoid unnecessary self-wakeup of per-CPU kthreadsShaohua Li
There are a number of cases where the RCU can find additional work for the per-CPU kthread within the context of that per-CPU kthread. In such cases, the per-CPU kthread is already running, so attempting to wake itself up does nothing except waste CPU cycles. This commit therefore checks to see if it is in the per-CPU kthread context, omitting the wakeup in this case. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Use kthread_create_on_node()Eric Dumazet
Commit a26ac2455ffc (move TREE_RCU from softirq to kthread) added per-CPU kthreads. However, kthread creation uses kthread_create(), which can put the kthread's stack and task struct on the wrong NUMA node. Therefore, use kthread_create_on_node() instead of kthread_create() so that the stacks and task structs are placed on the correct NUMA node. A similar change was carried out in commit 94dcf29a11b3 (kthread: use kthread_create_on_node()). Also change rcutorture's priority-boost-test kthread creation. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Tejun Heo <tj@kernel.org> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Andrew Morton <akpm@linux-foundation.org> CC: Andi Kleen <ak@linux.intel.com> CC: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-27Linux 3.1-rc8v3.1-rc8Linus Torvalds
2011-09-27Merge branch 'for-linus' of git://github.com/tiwai/soundLinus Torvalds
* 'for-linus' of git://github.com/tiwai/sound: ASoC: ssm2602: Re-enable oscillator after suspend ALSA: usb-audio: Check for possible chip NULL pointer before clearing probing flag ALSA: hda/realtek - Don't detect LO jack when identical with HP ALSA: hda/realtek - Avoid bogus HP-pin assignment ALSA: HDA: No power nids on 92HD93 ASoC: omap-mcbsp: Do not attempt to change DAI sysclk if stream is active
2011-09-27Merge branch 'pm-fixes' of git://github.com/rjwysocki/linux-pmLinus Torvalds
* 'pm-fixes' of git://github.com/rjwysocki/linux-pm: PM / Clocks: Do not acquire a mutex under a spinlock
2011-09-27Merge branch 'fix/asoc' into for-linusTakashi Iwai
2011-09-27vfs: remove LOOKUP_NO_AUTOMOUNT flagLinus Torvalds
That flag no longer makes sense, since we don't look up automount points as eagerly any more. Additionally, it turns out that the NO_AUTOMOUNT handling was buggy to begin with: it would avoid automounting even for cases where we really *needed* to do the automount handling, and could return ENOENT for autofs entries that hadn't been instantiated yet. With our new non-eager automount semantics, one discussion has been about adding a AT_AUTOMOUNT flag to vfs_fstatat (and thus the newfstatat() and fstatat64() system calls), but it's probably not worth it: you can always force at least directory automounting by simply adding the final '/' to the filename, which works for *all* of the stat family system calls, old and new. So AT_NO_AUTOMOUNT (and thus LOOKUP_NO_AUTOMOUNT) really were just a result of our bad default behavior. Acked-by: Ian Kent <raven@themaw.net> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-27ASoC: ssm2602: Re-enable oscillator after suspendLars-Peter Clausen
Currently the the internal oscillator is powered down when entering BIAS_OFF state, but not re-enabled when going back to BIAS_STANDBY. As a result the CODEC will stop working after suspend if the internal oscillator is used to generate the sysclock signal. This patch fixes it by clearing the appropriate bit in the power down register when the CODEC is re-enabled. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: stable@kernel.org
2011-09-26VFS: Fix the remaining automounter semantics regressionsTrond Myklebust
The concensus seems to be that system calls such as stat() etc should not trigger an automount. Neither should the l* versions. This patch therefore adds a LOOKUP_AUTOMOUNT flag to tag those lookups that _should_ trigger an automount on the last path element. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> [ Edited to leave out the cases that are already covered by LOOKUP_OPEN, LOOKUP_DIRECTORY and LOOKUP_CREATE - all of which also fundamentally force automounting for their own reasons - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26vfs pathname lookup: Add LOOKUP_AUTOMOUNT flagLinus Torvalds
Since we've now turned around and made LOOKUP_FOLLOW *not* force an automount, we want to add the ability to force an automount event on lookup even if we don't happen to have one of the other flags that force it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..) Most cases will never want to use this, since you'd normally want to delay automounting as long as possible, which usually implies LOOKUP_OPEN (when we open a file or directory, we really cannot avoid the automount any more). But Trond argued sufficiently forcefully that at a minimum bind mounting a file and quotactl will want to force the automount lookup. Some other cases (like nfs_follow_remote_path()) could use it too, although LOOKUP_DIRECTORY would work there as well. This commit just adds the flag and logic, no users yet, though. It also doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and was made irrelevant by the same change that made us not follow on LOOKUP_FOLLOW. Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Ian Kent <raven@themaw.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26Merge branch 'samsung-fixes-3' of git://github.com/kgene/linux-samsungLinus Torvalds
* 'samsung-fixes-3' of git://github.com/kgene/linux-samsung: ARM: EXYNOS4: Rename sclk_cam clocks for FIMC driver ARM: S5PV210: Rename sclk_cam clocks for FIMC media driver ARM: S5P: fix incorrect loop iterator usage on gpio-interrupt ARM: S3C2443: Fix bit-reset in setrate of clk_armdiv
2011-09-27ARM: EXYNOS4: Rename sclk_cam clocks for FIMC driverSylwester Nawrocki
The sclk_cam clocks are now controlled by the top level FIMC media device driver bound to "s5p-fimc-md" platform device. Rename sclk_cam clocks so they accessible by the corresponding driver. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>